The present invention relates generally to the field of animal litters, and particularly to litter formed of wood and sodium bicarbonate. The absorbent litter material is characterized by a pleasant odor, durability, good absorption, and is especially suitable for use as a small animal litter, which effectively absorbs animal waste materials and neutralizes associated unpleasant odors.
The control of pet urine odors is a chronic challenge for those who keep pets on litter, and especially when the litter is maintained in an indoor location. A variety of litter materials have been used, each with somewhat different characteristics, such as greater moisture absorption, comfort for the animal, and odor control by suppression, masking or elimination. Examples of past efforts to control odor include the use of wood shavings, such as white pine shavings, and by use of litter, which clumps upon exposure to moisture, and which urine soaked clumps can then be removed, leaving the non-soiled litter in the litter box for further use by the pet or other animal.
Previously, it has also been known to use aspen particles, chips, shavings, etc. as a litter for animals. However, this material has traditionally often been composed of all aspen, without other woods or substances introduced. Further, these 100% aspen litters were composed of essentially all portions of the tree, including the bark. Although such litters are suitable for use as horticultural mulch, the inclusion of the tree bark causes an appearance which is considered to be unsightly when the material is used as a litter, and particularly a litter for small animals, such as those which would be kept in a person's home, or for use in places of display, such as pet shops.
Other litter compositions including alfalfa or related forage crops are known for their utility as animal litters which effectively absorb animal waste materials and neutralize associated unpleasant odors. For example, alfalfa has been pelletized with starch, as disclosed in U.S. Pat. No. 3,923,005. Such pellets overcome the disadvantage of earlier pelletized alfalfa by reducing the problem of disintegration of the pellets, which caused the litter material to cling to the animal's feet.
A further improvement of alfalfa pellets was disclosed in U.S. Pat. No. 3,941,090, which discusses pelletizing cedar in combination with alfalfa binders.
U.S. Pat. No. 4,788,936 discloses pelleted bedding for livestock, which bedding includes 4 to 45% by volume of aspen bark, with the balance being a combination of sawdust, ground wood chips and ground lumber. U.S. Pat. No. 5,271,355 discloses absorbent material formed of pelletized poplar wood, preferably aspen, including the tree bark, and peat. Optionally, the material may also include cedar wood.
All of the above references involve absorbent materials that are completely pelletized. However, the process of pelletization is complex and thus expensive. Aspen is especially difficult to pelletize, because it is a hard, dry wood which exacts a toll on the extruding equipment used for the pelletizing process, by causing greater amounts of wear on the equipment parts, resulting in the expense of frequent maintenance and replacement.
U.S. Pat. No. 5,884,584, which issued to the patent application owner herein addressed an absorbent material suitable for animal litter formed of pine, alfalfa and poplar wood, in a specific percentage combination. While not pelletized, that mixture is highly absorbent and has a particularly attractive appearance.
The patent that issued to Cortigene, U.S. Pat. No. 4,203,388 discloses a litter which contains pelleted and dried cellulose-containing rejects of a paper-making fiber plant and deodorizer materials that may be sodium bicarbonate, the rejections of a secondary paper-making fiber plant consisting essentially of cellulose and mineral fill, and in which the rejects comprise a mixture of the waste rejects and paper broke. As discussed above, the present invention is not a pelleted product and is formed of clean wood, rather than recycled or bark-bearing wood, so as to be especially fresh smelling and absorbent.